Some of the components of the blood of a mammal are listed. Which two of these components are involved in attacking bacteria and other organisms that cause disease? 1) antibodies
2)fibrinogen
3)Platelets
4)White cells

A) 1 and 2
B) 1 and 4
C) 2 and 3
D) 3 and 4

How does the author's purpose in this passage differ from an author writing about her personal struggle living with asthma?

Environmental differences within ecosystems are generally caused by

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.